That is because she has had obesity surgery. A band has been fitted around the top of her stomach so she physically can't eat more than a few mouthfuls at a time.

The 46year-old from Bristol said: "I was on numerous diets, taking lots of slimming pills, trying lots of diets, soup diets, etc and just decided to do something more permanent."

Jilly was turned down for the operation by the NHS, because she was not obese - just overweight. But she found a doctor who would operate on her privately - in Belgium.

Band tightened

A few weeks after the operation she had another consultation at his London clinic.

Jilly Trella needed emergency surgery

He expanded her band by injecting liquid into it to restrict what she can eat. But the band was tightened too much.

By the time she realised, her surgeon was back in Belgium and unavailable.

Jilly said: "I started feeling unwell. I couldn't swallow or eat any liquids at all, over the weekend I got worse to such an extent I couldn't swallow my own saliva. I was starting to panic.

"We managed to get his assistant and she said to go on their website and download some information on how to take the solution out of the gastric band. Print it off and take it to my doctor."

Jilly ended up being treated as an emergency by the NHS.

Survey

A survey by BBC News was sent to all members of BOSS, the British Obesity Surgery Society.

Matthew should not have been offered surgery

Twenty-one surgeons answered our questions, who, it is estimated, carry out 60% of procedures in the UK.

All said that In 2007 they had treated patients who had their surgery abroad.

And over half said they had seen patients who had suffered "long term damage" because of a "lack of after care".

Alberic Fiennes, BOSS secretary, said most of the treatment which is essential for the band to work happens in the two years after the operation.

He said: "The problem is the safety of gastric banding rests entirely on patients having immediate access every day of the year to informed medical care, somebody who is able, competent and understands their need for immediate adjustments for gastric bands.

"It is difficult to see how that can be provided across the English channel."

There also are another issue that British surgeons are concerned about.

Undercover investigation

A patient's Body Mass Index (BMI), is a ratio of weight to height.

People are queuing up to have cosmetic procedures under general anaesthetic, having parts of their bodies chopped away because they feel like it

Shaw SomersBritish Obesity Surgery Society

International guidelines say patients should have a BMI of at least 40 to be considered for obesity surgery.

If they have another serious weight related condition such as diabetes, it can be 35 and over, or in rare cases as low as 30.

During our research we had been told that another surgeon in Belgium was prepared to operate below international guidelines.

Wearing a hidden camera I posed as a prospective patient and went to see Dr Christiaan De Bruyne at one of his central London consultations.

In an ornately furnished room I explained my BMI was 29.8, and that I was healthy.

He told me: "If you gain two kilos you will be 30.5. It's not about the 2kg, it is about your motivated to do it."

To be absolutely clear, I asked for clarification: "I don't want to get over there, pay the money, and you say you can't do me for some reason".

He said: "If you go to Belgium I have never have to put a patient back. Never.

"It's my reputation. I see you here, you are at the limit, no problem it can be done."

Inappropriate treatment

We showed the footage to leading London surgeon Alberic Fiennes who said: "The slightest risk that it would have put you at would have been an unnecessary risk because it was inappropriate treatment in the first place."

GASTRIC BAND

A fluid-filled balloon is clipped around the upper end of the stomach with a band

This restricts the flow of food into the lower stomach, making the patient feel full sooner

The band can be adjusted via the reservoir which is sited beneath the skin

He is not alone in being concerned. Our survey revealed that half the surgeons who responded also said they had seen patients treated abroad to whom they would not have offered surgery.

One key member of BOSS, Shaw Somers, said this is because some no longer see surgery for the serious invasive procedure he says it is.

"People are queuing up to have cosmetic procedures under general anaesthetic, having parts of their bodies chopped away because they feel like it.

"Unfortunately, obesity surgery is being seen as much the same and its quite different."

The surgery Dr de Bruyne offered is not illegal - international guidelines are not binding.

However, he refused to answer our questions, and threatened legal action.

The President of SOSB (Section of Obesity and Metabolic Surgery in Belgium) believes this kind of practice is an exception, and that the vast majority of surgeons do respect international guidelines.

He added that in his personal opinion, offering gastric banding to a patient with a BMI of 29 is 'unethical'.

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